Action Points

Note that these analyses were published as abstracts and presented orally at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.

SAN FRANCISCO, May 7 -- When it comes to starting antihypertensive therapy, one drug class may be as good as another for cardiovascular prevention, researchers said here.

All classes significantly prevented stroke compared with placebo or no treatment, and all but angiotensin-receptor blockers (ARBs) did the same for coronary heart disease events, William Elliott, M.D., Ph.D., of RUSH Medical College in Chicago, and colleagues found.

Compared with standard diuretics, the only outcome difference among the agents was a higher stroke rate with ACE inhibitors and beta-blockers, they reported at the American Society of Hypertension meeting.

No differences were seen among commonly used diuretics.

These findings of similarity between agents should be reassuring for patients, Dr. Elliott said. "People should feel comfortable with whatever their doctor gives them."

The researchers' "network" analysis of data from all published outcome-based clinical trials of initial antihypertensive therapy allowed comparisons between drugs classes that have never been made directly head-to-head, Dr. Elliott noted.

For example, ARBs -- the relatively new kid on the block among blood pressure-lowering drug classes with the least clinical trial experience in the initial agent setting -- had never been pitted against diuretics.

In the meta-analysis, ARBs weren't significantly less effective than diuretics for prevention of heart attack and heart disease-related death (odds ratio 1.11, 95% confidence interval 0.94 to 1.32).

ARBs also kept up with diuretics for stroke prevention (OR 1.10, 95% CI 0.96 to 1.26).

However, it was the only agent that couldn't significantly beat placebo for coronary heart disease events, Dr. Elliott said. He chalked that up to lower statistical power.

The meta-analysis included a total of 269,180 hypertensive patients in 60 clinical trials with at least one year of follow-up for stroke and 276,396 patients in 57 trials for coronary heart disease events.

Stroke risk with a calcium channel blocker as initial treatment was identical compared with a diuretic. Both were slightly better than ARBs and significantly better than ACE inhibitors and beta-blockers.

Risk of coronary heart disease events -- MI or heart disease-related death -- was not significantly different from diuretics for any of the other classes, although ACE inhibitors were significantly better than ARBs or beta-blockers.

The reason for the difference between ACE inhibitors and ARBs might have been simply that the ACE inhibitors are better studied, whereas the benefits of calcium channel blockers in the stroke analysis may have been due to pleiotropic effects on regression of carotid plaque, Dr. Elliott said.

It was surprising that calcium channel blockers did so well against diuretics, commented ASH president Henry Black, M.D., who moderated the press conference at which the results were released.

But he cautioned that the meta-analysis did not consider heart failure events, which calcium channel blockers have previously been shown to increase.

Among the diuretics, patients given hydrochlorothiazide were at virtually the same stroke and coronary event risk as those given chlorthalidone, Dr. Elliott noted. "A diuretic is a diuretic is a diuretic."

The findings remained virtually unchanged by Bayesian analysis and by adding additional, less specific data from trials that looked at dual initial therapy (ACCOMPLISH), used "add-on" drug therapy, or included nonhypertensive participants.

More importantly, "the reality is that well over 90% of patients will need two or more drugs to control their blood pressure anyway," Dr. Elliott acknowledged.

Nevertheless, better initial treatment may get patients to goal faster. And "every campaign begins with a single strike," he said.

Dr. Elliott reported serving as a consultant to Novartis and sanofi-aventis; serving on the speakers bureau of Novartis, Pfizer, Bristol-Myers Squibb/Sanofi-Synthelabo Partnership, and sanofi-aventis; and receiving royalties from Elsevier.